The present invention relates to a stop valve which is particularly adapted for use on faucets or shower heads for temporarily cutting off the flow of water therethrough. In the last couple of years, the western portion of the country has been suffering from severe drought conditions and, accordingly, considerable work has been done in the field of water conservation. However, two of the most open and notorious areas of water waste which have received little or no attention are found in the use of home faucets, particularly bathroom faucets and showers. Typically, when using the bathroom faucet for shaving or washing, the water is first brought up to a comfortable temperature and allowed to continually run throughout the entire shaving or washing operation thereby resulting in a considerable amount of water waste. People are very reluctant to periodically shut off the water flow after rinsing their razor or wetting their face for fear of a drop in water temperature when the water is again turned on. Accordingly, all efforts to change people's washing habits in an effort to conserve water have proved unsuccessful.
The use of showers presents a quite similar problem to that of the bathroom faucet in that people are unwilling to use the shower solely for wetting and rinsing purposes due to the difficulty in maintaining a comfortable water temperature. While some shower control devices are so constructed that the temperature can be maintained, the majority of older showers have separate hot and cold controls making this form of home water conservation a less than pleasing experience. It would therefore be highly desirable to provide a stop valve which can be easily installed on existing faucets and showers for periodically cutting off the water flow therethrough without appreciably affecting water temperature. With such a device installed, the water flow through faucets and showers could comfortably be limited to wetting and rinsing and thereby eliminate the tremendous water waste which otherwise results from the conventional continuous water flow whenever faucets or showers are in use.